What is a major strength of the longitudinal design?

Correct Answer: A

Rationale: A major strength of the longitudinal design is that researchers can examine relationships between early and later behaviors. This design allows researchers to observe and track changes in the same participants over an extended period of time, providing valuable insights into developmental trajectories and how behaviors are connected across different stages of life. Choice B is incorrect because longitudinal studies track changes over time, not necessarily collect a large amount of data in a short time span. Choice C is incorrect as it refers to cross-sectional studies rather than longitudinal studies. Choice D is incorrect as it describes a cross-sectional design where participants of different ages are studied at the same time.

Correct Answer: D

Rationale: When children are research participants, it is essential to obtain informed consent from their parents or others who act on their behalf. This is to ensure that the child's rights and well-being are protected during the research process. Informed consent is a fundamental ethical principle in research involving children, as they may not have the capacity to fully understand the implications of their participation. Choice A is incorrect because seeking the opinion of others when in doubt about harmful effects is not a substitute for informed consent. Choice B is incorrect because children do not have an absolute right to conceal their identity in research, especially when it comes to ensuring their safety and well-being. Choice C is incorrect as it is important to inform children or their parents about the results of the research to maintain transparency and respect for their participation.

Correct Answer: D

Rationale: The male produces sperm in the testes, which are two glands located in the scrotum. The scrotum is the external sac that houses and protects the testes, allowing for optimal temperature regulation to support sperm production. Choice A is incorrect because sperm production does not occur in the penis. Choice B is incorrect because the scrotum houses the testes, not the penis. Choice C is incorrect because sperm is produced in the testes, not the penis.

Correct Answer: A

Rationale: When the blastocyst burrows deep into the uterine lining, this process is known as implantation. Implantation is a crucial step in the early stages of pregnancy where the blastocyst attaches to the uterine wall in order to receive nourishment and continue developing. Choice B is incorrect because implantation is a necessary step for pregnancy to occur. Choice C is incorrect as implantation marks the beginning of further growth and development. Choice D is incorrect as the duplication of cells occurs during earlier stages of development, not during implantation.

Correct Answer: C

Rationale: The correct answer is C: embryo. The most rapid prenatal changes occur during the embryo stage, which spans from approximately 2 to 8 weeks after conception. This period is crucial as major organs and systems of the body develop rapidly, laying the foundation for future growth and development. The zygote stage is the initial single-celled entity formed by the union of sperm and egg, while the blastocyst stage involves the cluster of cells resulting from the zygote dividing and growing. The fetus stage follows the embryo stage and focuses on refining and growing existing structures rather than rapid development. Therefore, the embryo stage is where the most significant and rapid changes take place in prenatal development.